1. Field of the Invention
The present invention relates to a displacement detection system of an optical touch panel and method thereof, and more particularly, to a displacement detection system of an optical touch panel and method thereof capable of correcting output coordinates according to a displacement.
2. Description of the Prior Art
A traditional optical touch panel utilizes a light source to light a panel, and an image sensor to capture an image including an image of an object. The optical touch panel utilizes luminance information of the object to calculate a center of gravity of the object, so the center of gravity of the object obtained according to the luminance information of the object may be biased to one side of the panel when the object moves across corners of the panel. In this situation, although the object moves straight forward, the image sensor may capture a curved image of the object when the object moves across corners of the panel. Please refer to FIG. 1. FIG. 1 is a diagram illustrating the image sensor capturing the uncorrected image of the object when the object moves across corners of the panel. As shown in FIG. 1, the center of gravity of the object obtained according to the luminance information of the object may be biased to one side of the panel because the object moves from a light/dark area to a light/dark area of the panel.
The prior art utilizes a center of the object to calculate shadow points for improving the above mentioned situation. But quality of interpolation calculation is poor in the prior art utilizing the center of the object, and may result in sawtooth images appearing when the object moves slowly.